1. Field of the Present Invention
The present invention relates to an ink set for ink jet, an ink jet recording method, and an ink jet recording apparatus.
2. Description of the Related Art
So-called ink-jet methods for ejecting a liquid or molten solid ink through an ink discharging port such as a nozzle, slit or porous film have been used for many printers since a printer using such a method is compact and inexpensive. A piezo ink-jet method for ejecting an ink by taking advantage of deformation of a piezoelectric element, a thermal ink-jet method for ejecting an ink by taking advantage of boiling of the ink by thermal energy, and the like are frequently used among the ink-jet methods since these methods enable high-resolution, high-speed printing. Ink-jet printers are used for printing on a paper sheet such as a regular paper sheet or an ink-jet paper sheet as well as on a film such as an OHP sheet and on cloth.
One of the currently important objects of the ink-jet printer is high speed and high quality printing of images. For attaining compatibility between high speed printing and high quality printing of an image, Japanese Patent No. 2667401 discloses a method comprising the steps of allowing a liquid containing a cationic group-bearing compound to adhere on a recording medium, allowing the liquid to permeate into the recording medium, and forming an image by allowing an anion dye-containing ink to adhere on the surface of the recording medium immediately after the liquid has been absorbed into the recording medium and has disappeared from the surface thereof. However, image density may be insufficient in this method when the drying time of the ink is shortened, and long-term reliability may be insufficient when the images are printed using a small volume of drops.
In order to prevent the scorching of an ink and enhance the ejecting stability of an ink, an ink containing an anionic dye, water, a compound forming a hardly soluble complex with a polyvalent metal, and an inorganic sulfate which makes the polyvalent metal water soluble are proposed in Japanese Patent Application Laid-Open (JP-A) No. 8-337747 and the like. The method is a method of stabilizing the polyvalent metal ion by use of the inorganic sulfate in order to prevent the insolubilization of a dye and the like, for example, by the polyvalent metal ions which are eluted from metal members such as an ink flow path. When the ink is mixed with a liquid containing the polyvalent metal, coagulation therefore the life of a maintenance unit has often been sometimes insufficient.
As described above, conventional methods have not been able to simultaneously satisfy optical density, feathering, intercolor bleeding, drying time and reliability of a maintenance unit.